Speed-indicator



Patented Mar. 7, I899.

D. T. SHARPLES.

' SPEED mmcAmR,

(Application filed Dec. 8, 1897.)

(No Model.)

. a: i l I Witnesses.

( jaudi t Jr flw Inventor.

Attorney.

' form of my device.

llwrrn Starts DAVID T. SHARPLES', OF ELGIN, ILLINOIS.

SPEED -lilDlCATR.

SPECIFICATION forming part of Letters Patent No. 620,723, dated March*7, 1899.

Application filed December 8, 1897- Serial No. 661,173. (No model.)

To 60% whom it may concermy Be it known that I, DAVID T. SHARPLES, acitizen of the United States, residing at Elgin, county of Kane, Stateof Illinois, have invented certain Improvements in CentrifugalSpeed-Indicators, of which the following is a specification.

My invention relates to an improved speedlndicator operating bycentrifugal force.

it is especially applicable to machines intended to be run at a certainspeed, any variation from which should be automatically indicated.

Heretofore speed-indicators have, been devised in which the centrifugalmovement of a weighted member is made to operate through intermediatemechanism upon a suitable pointer. In myimproved device all intermediatemechanism is dispensed with, the centrifugally-moving member being madeto serve directly as an indicator.

lhe invention is fully described in connection with the accompanyingdrawings and is specifically set out in the claims.

Figure 1 is a sectional elevation of one Fig. 2 is a plan view of thesame. Figs. 3 and 4 are similar views of a modified constructionembodying my invention.

Referring specifically to the construction shown in Figs. 1 and 2, Arepresents a casing, which, as shown, has a base-plate A, adapted to beattached to the spindle B which is to be speeded. "Within this casing,which is rotated with the spindle, is mounted a movable arm or disk C,which is adapted to serve directly as an index. This index arm or memberis in the present construction pivoted at a point 0 to the casing, sothat its free end 0 shall swing directly across the center of rotationof the whole device'that is, across the axis B. This free end 0 isweighted at 0', so that it will tend to move outward in the direction ofthe arrow under the influence of' the centrifugal force developed. bythe rotation of the spindle. This centrifugal movement is regulated by asuitable spring, as S, the yielding of which allows the portion 0 of theindex which is normally held in the position indicated in Fig. 2 to movetoward the center B as the speed of rotation is increased.

It will be readily seen that at a certain speed of rotation a certainpoint of the portion 0 of the index member 0 will be directly at thecenter of rotation. If, therefore, a certain marking-as, for instance, ablue spot or circle fbe placed at this point, it will only be necessaryto provide a sight, as a, at the center of the casing to enable theoperator to see at a glance that the desired speed is being maintained.Othermarkings -as, for instace, a white one at e and ared one at 9 wouldindicate speeds respectively lessand greater than that indicated by theblue. It will be understood that any marking which is at the center ofrotation will be seen as distinctly as though it were stationarynotwithstanding the high speed at which the whole device may be rotated.

The tension of the spring may be varied so as to accurately regulatefthemovement? The sight (2. may be merely a central opening in the top of ametallic casing, as shown, preferably covered bya glass (1, so as toentirely exclude dust, dirt, 53C.

It is evident that the construction above described may be readilymodified without departing from. the spirit of my inventionfor instance,as shown in Fi s. 3 and' l, where the index member 0 is in the form ofaplun; ger-rod, hollow except at the head 0 and having a series ofmarkings in the form ofbands c f g. This plunger, as indicated, isloosely mounted in a glass tube A which is lined diametrically in themain casing A, attachable to the spindle. It operates in a mannerexactly similar to that previously described, moving outwardcentrifugally against a spring S and showing at the center a the markingwhich corresponds with the speed of rotation. Other modifications may bereadily devised. For instance, the casing may be fixed instead ofrotating with the frame which carries the centrifugal index member. Alsothe spindle 13, instead of being rotated, may

be fixed and the indicator mechanism rotated upon it. The markings onthe centrifugal index member need not be arranged to swing over the trueaxial center, as described, but

may be made to enter the sight provided in any desired manner adapted toshow directly the position of the same and thereby indicate 5 the speedof rotation.

What I claim is 1. A speed-indicator having an index member arranged tobe rotated bodily with the object to be speeded and to directly indicateby its centrifugal position the speed of rotation, substantially as setforth.

2. A speed-indicator having a casing with a sight in the face thereofand an index memher having a centrifugal movementinto said I 5 sight,substantially as set forth.

3. A speed-indicator having a casing with a sight at the center ofrotation and an index member having a centrifugal movement into saidsight, substantially as descri 4. A speed-indicator comprising a rotaryI0 casing with central sight, an index member mounted therein and havinga. mark ormlrb ings thereon adapted to swing centrifu'gflly' in presenceof two witnesses.

. DAVID T. SHARPLES- Witnesses:

K. E. MoREY, C. S. GARLISLE.

